1. Field of the Invention
The present invention relates to a wrench, and more particularly to a wrench having a pivotal handle adjustable to various angular position relative to the driving cartridge or the driving head.
2. Description of the Prior Art
Typical flex-head wrenches comprise a handle pivotally connected to a tool head, and a locking mechanism having a unitary locking spool seated within the handle and manipulated to lock or unlock the tool head at a desired angular position with respect to the handle.
For example, U.S. Pat. No. 5,199,335 to Arnold et al. discloses one of the typical flex-head wrenches comprising a unitary locking spool seated within a handle and having a cooperating series of teeth extending around a portion of the spool, for engaging with the corresponding teeth of a hub of the tool head, to lock the handle to the tool head in place.
However, the engagement of the teeth of the spool with the corresponding teeth of the hub of the tool head is similar to the typical ratchet mechanism for tools, and the spool may be easily forced to move along a longitudinal axis of the spool that is perpendicular to the tool head, and the spool is parallel to the rotational or moving plane of the handle, such that the spool may have a good chance to be easily forced to move out of or to be disengaged from the tool head when the handle is rotated relative to the tool head.
U.S. Pat. No. 6,216,567 to Hu discloses another similar typical flex-head wrench comprising a handle pivotally connected to a tool head, and a catch slidably engaged in a longitudinal hole of one end of the handle, and a push button rotatably and slidably engaged in a transverse hole of the handle and having a projected supporting surface for engaging with the catch, and for forcing the catch to engage with and to lock the tool head.
However, the push button is rotatably and slidably engaged in the transverse hole of the handle, and thus may have a good chance to be rotated relative to the handle, and thus to disengage the projected supporting surface from the catch, and such that the push button may not be used for suitably locking and unlocking the tool head with the catch.
U.S. Pat. No. 6,216,565 to McCann discloses a further typical flex-head wrench comprising a handle pivotally connected to a tool head and rotatable relative to the tool head in a rotating plane parallel to the plane of the tool head, and a pawl slidably disposed between a driving cartridge and the handle to selectively couple and lock the driving cartridge to the handle at the required or selected angular position.
An additional barrel is further required to be provided and disposed between the driving cartridge and the handle, to enclose the pawl therein, and includes one or more projections extended therein to engage with the pawl, and to move the pawl up and down to engage with teeth of a shaft, and to selectively lock and unlock the driving cartridge to the handle.
However, the provision and the engagement of the pawl and the barrel between the driving cartridge and the handle may increase the distance between the driving cartridge and the handle, and thus may increase the driving instability of the driving cartridge by the handle.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional wrenches.